After the withdrawal of the US and NATO troops from Afghanistan by September 11, India will have tremendous concern on the resurgence of the Taliban and the wartorn country being used as a safe haven for terrorists, according to experts here. US President Joe Biden on Wednesday announced that all American troops would be withdrawn from Afghanistan by September 11 this year to end the country’s longest war. Following suit, the North Atlantic Treaty Organisation (NATO) said it will also pull out its troops from Afghanistan.